Gay and bisexual men who use apps to meet strangers for sex have been warned about personal safety fears following the conviction of serial killer Stephen Port.

Port murdered four men he met through sites Grindr, Sleepyboys, Bender and LadsLads and raped and sexually assaulted others.

The case was the third this month involving gay men who had been killed by people they met on the apps.

Stephen Port was today convicted of murdering four men he met on gay dating apps

Police have issued a warning to those using so-called 'hook-up' apps like Grindr

Satanist Stefano Brizzi strangled a policeman he met through Grindr before dissolving his body in acid, while 18-year-old Ben Bamford was jailed for 16 years for stabbing a civil servant he met through the app.

Police have stressed that users should meet in a public place for the first time, not someone's home, be careful about what they eat or drink in case it has been spiked with drugs, and tell someone else where they are going.

Detective Chief Inspector Tim Duffield, who led the successful investigation into Port's string of killings and sex attacks, said: 'From my perspective, the advent of social media platforms has made it really, really easy to hook up with people anonymously.

Scotland Yard Commander Stuart Cundy warned there is a 'fine line' between what is thought to be 'safe' use of the drug GHB, and death.

He said: 'There is such a fine line between using it for heightened sexual acts, through to unconsciousness, through to death. It is a real fine balance.

'GHB is a dangerous drug. For those that use it, they will understand that there is always that fine line. In the case where it's not just been taken once, it's been taken again, so what might be considered a safe dose at one point is then added to by taking it at some point in time later, you need to be a very proficient medical expert to truly understand what would be safe and what wouldn't be safe.'

DARK SIDE OF THE WEB: HOW A SERIES OF PREDATORS HAVE USED THE INTERNET TO SNARE THEIR VICTIMS

The conviction of serial killer Stephen Port has raised the issue of online dating safety. Here are some other recent examples.

- Stefano Brizzi, 50, is facing life in jail for strangling Pc Gordon Semple during a sex game gone wrong at his Southwark flat after hooking up on Grindr.

- Ben Bamford, at the time aged 17, was found guilty at Lewes Crown Court of murdering high-ranking HM Revenue and Customs official Paul Jefferies, 52, who he met on Grindr. He was sentenced to life with a minimum term of 16 years.

Stefano Brizzi (left) strangled Pc Gordon Semple after meeting him on Grindr. Ben Bamford murdered a civil servant he met through the same app

- Former teacher Gary Pearce, from Sidcup in Kent, was jailed for five years last September for grooming a 14-year-old boy he met on Grindr.

- Met Police officer Pc James Evans, 26, was jailed for four years in August after having sex with a child rape victim he met online. He exchanged dozens of 'sex talk' messages with the vulnerable 15-year-old schoolgirl on the Tinder dating app.

- In July, Miles Donnelly, 35, admitted murdering 44-year-old single mother Usha Patel who he met on dating website Oasis. He killed her in a 'drunken rage' at her home in north west London.

Single mother Usha Patel was murdered after meeting her killer on a dating site Oasis

- In February 2015, psychology graduate Darren Scott, 26, was convicted of the attempted murder of a rich friend he met on Grindr. He repeatedly stabbed his victim at his £2million home in Mayfair, central London.

- American fake FBI agent Sammy Almahri, 45, was jailed for life in November for murdering Cardiff woman Nadine Aburas, 28. The couple met via the internet dating site MuslimMatch.com in 2013.

- In September, maths teacher Christopher Stephenson, 32, from York, was jailed for 20 months after having a sexual relationship with a pupil. The pair began communicating online in the summer of 2007 after she 'poked' him on Facebook.

- Paedophile rapper Daniel Rodriguez, also known as Grymey D, groomed schoolgirls on social media before filming himself having sex with them. The 28-year-old from Hackney, who was jailed for 16 years, used Instagram, Facebook and Blackberry Messenger to contact girls who he invited to his home.